Paper making and fiber liberation – Processes and products – Non-fiber additive
Patent
1995-05-31
1999-01-12
Silverman, Stanley S.
Paper making and fiber liberation
Processes and products
Non-fiber additive
1621681, 162189, 1621683, D21H 1720, D21H 1737, D21H 2326
Patent
active
058581731
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/US95/00187 filed Jan. 6, 1995.
1. Field of the Invention
The present invention is directed to the papermaking arts, more particularly to a process for the manufacture of a paper having improved grease and water resistance, yet facilitating recycling of the paper. Such papers (throughout the specification and claims "papers" includes virgin or recycled paper, kraft stock and similar materials) find particular application in the container making art wherein such improved properties are desirable. The container making art, particularly, in the field of corrugated containers, folding cartons, and the tray and box industries, consumes much of the natural timber resources. Thus, it would be beneficial to formulate new processes of forming papers of improved grease and water resistance properties which would be recyclable.
2. Description of the Related Art
The art of "papermaking" is an ancient one, being attributable to invention by the Chinese before the birth of Christ.
More modern developments resulted in the widely accepted Fourdrinier process (See Kirk-Othmer Encyclopedia of Chemical Technology, 3rd ed., Vol. 9, pp. 846-7, John Wiley & Sons, New York 1980) in which a "furnish" (a "furnish" is predominantly water, e.g., 99.5% by weight and 0.5% "stock" ("stock" being virgin, recycled or mixed virgin and recycled pulp of wood fibers, fillers, sizing and/or dyes) is deposited from a headbox on a "wire" (a fast-moving foraminous conveyor belt or screen) which serves as a table to form the paper. As the furnish moves along, gravity and suction boxes under the wire draw the water out. The volume and density of the material and the speed at which it flows onto the wire determine the paper's final weight.
Typically, after the paper leaves the "wet end" of the papermaking machine, it still contains a predominant amount of water. Therefore, the paper enters a press section, which can be a series of heavy rotating cylinders, which press the water from the paper, further compacting it and reducing its water content, typically to 70% by weight.
Subsequent to pressing the paper enters a drying section. Typically, a drying section is the longest part of the paper machine. Hot air or steam heated cylinders contact both sides of the paper, evaporating the water to a low level, e.g., 5% by weight of the paper.
The paper optionally passes through a sizing liquid to make it less porous and to help printing inks remain on the surface instead of penetrating the paper. The paper can go through additional dryers that evaporate the liquid in the sizing and coating. Calenders or polished steel rolls make the paper even smoother and more compact. While most calenders add gloss, some calenders are used to create a dull or matte finish.
The paper is wound onto a "parent" reel and taken off the paper making machine.
The paper on the parent reel can be further processed, such as on a slitter/winder, into rolls of smaller size or fed into sheeters, such as folio or cut-size sheeters, for printing end uses or even office application.
In order to make containers, rolls formed by slitter/winder (e.g., of paper and kraft grades of liner) are unwound and coated with a wax. Waxes impart water resistance and wet strength to the liner but inhibits recycling the used containers incorporating them. Additionally, the prior art wax coated liners must be adhered to the other components of the container with hot melt adhesives. These hot melt adhesives are a further impediment to recycling of formed containers employing wax coated components. Thus, there still exists a need for manufacturing paper possessing superior wet strength and water and grease resistance properties but facilitating recycling thereof.
SUMMARY OF THE INVENTION
In one embodiment the invention is directed to a process for making paper wherein a furnish is deposited on a wire and dewatered, characterized in:
adding to the furnish a recyclable plastic coating.
In another embodiment, the invention is directed to a process for making paper wherein a f
REFERENCES:
patent: 2970079 (1961-01-01), Klacsmann
patent: 3901857 (1975-08-01), Sackman et al.
patent: 4088530 (1978-05-01), Chan et al.
patent: 4167439 (1979-09-01), Killam
patent: 4225383 (1980-09-01), McReynolds
patent: 4313790 (1982-02-01), Pelton et al.
patent: 4510019 (1985-04-01), Bartelloni
patent: 4798653 (1989-01-01), Rushmere
patent: 4845148 (1989-07-01), Moore et al.
patent: 5160484 (1992-11-01), Nicoloff
patent: 5176797 (1993-01-01), Hartan et al.
patent: 5393566 (1995-02-01), Propst, Jr.
patent: 5429294 (1995-07-01), Propst
patent: 5492733 (1996-02-01), D'Anna et al.
Fortuna Jos'e A.
Silverman Stanley S.
Tim-Bar Corporation
LandOfFree
Paper making process does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Paper making process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Paper making process will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1510696